Production of plastic substance.



UNITED STATES PATENT OFFICE.

JONAS W. AYLSWOBTH, OF EAST ORANGE, NEW JERSEY, ASSIGNOB TO CONDENSITE COMPANY OF AMERICA, OI GLEN.BIDGE, NEW JERSEY, A CORPORATION O! m JERSEY.

PRODUCTION OF PLASTIC SUBSTANCE.

No Drawing.

same, Serial No. 780,453, filed July 22,1913,

I have described a process for producing plastic compositions which in one form, comprises the formation of an alkaline- -water solution of a phenol resin, or fusible, soluble, phenol-formaldehyde condensation product, by -the aid of an oxid or hydroxid of an alkali metal or alkaline earth metal. Hav" obtained such a, water solution, in the said form of my process described in 2 said application, the same is mixed with a fibrous or cellular filling body, which is thereby caused to swell and absorb the alkaline solution. The alkali in the solution is then'neutralized by an acid, as described,

with the result that water-insoluble, insulating, precipitates are formed, in and about the pores and fibers of the filling body, of-

i the phenol'resin and of a salt of the alkali used in the solution. Or, if no fillin body 3- is used, the neutralization of the a kaline water solution results in the formation-of the same two precipitates, the resultant intermixed mass being valuable .as a binder, or to be used by itself as a plastic compo- 40 sition, either with or without the addition of a methylene-containing hardening agent adapted to cause the further hardening of the mass to infusibility upon subsequent heating. In the present application will be described a principal process in which phenol and formaldehyde are mixed initiallv with water and an alkaline earth, caused to react to form a substance comprising phenol-alcohols in alkaline water-solution, neutralized,

and the alkali precipitated as a water-insoluble, insulating salt. This rocess is carried out either with or without t e use of a filling material, and if the same is. used, the neutralization of the solution may take place;

Specification. of Letters Patent.

' Application filed August 4, 1918. Serial No. 782,942.

Patented Sept. 22, 1914.

before or after the filler is added. After neutralization the salt of the alkali thereby formed may be readily eliminated, or may remain as a useful ingredient of the mass as afiller. In this process the phenol-formalco dehyde reaction product is not precipitated by the neutralization of the alkali as was the phenol resin in my a plication referred to a s above, and, while t e present process utilizes some of the steps of my other -procc5 ess referred to, it is, as a whole, a quite different method. 'In the present process the mass, after neutralization, may be dried and subsequently molded or compressed and hardened by further reaction with heat, and the addition of a further amount of a methylene-containing ingredient, if desired, to form a desired article. My object is accordingly to provide an improved process for the formatmii of phenolic condensation products, of the chameter outlined above and thereb to form plast1c compositions of high] esirable properties, all as will morefully appear hereinafter in the following specification and appended claims. I My present invention, as well as that described in myother application referred to, is adapted to form two classes of compositions; one a composition which requires only j to be compressed in heated condition, by which means a compact, hard mass is ob-. tained without any conversion into a nonplastic or infusible state, and the other, a. composition which is converted by further reaction under the application ofeheat or heat and pressure into-a non-plastic, infusible and insoluble condition. The first class of compositions are rapid molding, the second class ordinarily require more time in molding, but are better adapted for uses requiring high heat resistance, chemical inertness, high dielectric strength and great mechanical strength.

In my princi al process, briefly referred to above, I first orm a water-soluble phenolformaldehyde condensation product by reaction between phenol or cresol and formaldehyde, in the presence of an alkaline earth metal oxid or hydroxid, either in small or large amounts, that is, in less than an equimolecular proportion of the alkaline earth metal oz'cid, or in a full equi-molecular pro portion of the same, The product thus formed, is, as stated, largely composed of application referred to,-is obviated.

The neutralization of the alkaline earth metal oxid used in this process may be effected either prior to compounding the mass with a suitable filler, if the same is desired in the plastic mass finally produced, or subsequent thereto. The neutralization is effected by an acid which will form a nonwater-soluble, insulating, salt with the alkaline earth metal oxid used, suitable acids being sulfuric and carbonic acids. The reaction product'in its water solution may be entirely precipitation with sulfuric or carbonic aci followed by filtration, and may. thereafter be used as a binding agent in the formation of a plastic composition, or as a lacquer or varnish which is capable of conversion, after drying, into a more highly condensed nonwater soluble resinous product, or into a hard infusible, insoluble condensation product, dependent on the proportion of formaldehyde or methylene groups in the composition entering into reaction.

The use of basic oxids or hydroxids as agents of condensation with phenols and formaldehyde in widely varyin percentages is well known in this art but t e usefulness of such condensing agents has been very limited because their presence in the finished product impairs the quality of the product, and furthermore, they cannot be re'adil removed by gay of the well known workmgmethods.

en'their removal has'been attempted, a certain proportion of the condensing agent has remained in the product, with harmful results for many purposes to which the composition may be put. It has been proposed, because of the recognized difiiculty of removing the condensation agents from the product, to employ the same in very small proportions. By my present inventlon, I am enabled to use a substantial proportion of condensing agent, in the form of an alkaline earth metal oxid and to overcome the previous objections to the useof the same given above, by converting it into an insoluble, insulating salt, or precipitate, which may remain in the product or may be removed by filtration after the basic oxid has performed its function of acceleratin condensation and of forming a water-solule product. The use of bases in considerable proportion favors the production of oxy-benzyl-aloohols which are soluble in water and in water containin' free phenols, and these products are capab e of further reaction to form-resinous non-water soluble bodies and hard, infusible,

insoluble, bodies.

freed from the alkaline earth, b

r I have found that when phenol andformaldehyde are caused to react in 'e'qui-molesular proportions in the-presence of a substantial roportion of an alkaline agent, such as ime, there always results a considerable proportion of free phenol in the produ even though the reaction was so condu that there is no eva oration loss of formaldehyde.

Further, in or er to reduce the proportion of this free phenol andform a more or less complete condensation of the phenol to phenol alcohols, a lar e excess of formaldehydeabove the eqlu-molecular roportion must be uxd. 1 have observed at under the above conditions, that is, where a large excess of formaldehyde is used not only are plhenol alcohols formed, but a so a part of t e formaldehyde is condensed by the aldol condensation toJormOse, and is lost or rendered ineffective in the main reaction desired. The disap rance of formaldehyde in this manner as led some investigators to assume that formaldehyde combined with phenol in greater than equimolecular proportion, one investigator concludin that in this reaction one phenol molecu e is present to every two molecules of formaldehyde. My experiments have demonstrated, however, that the excess formaldehyde used in such cases has largely been transformed into formom-like impurities, as stated. I therefore find it advisab 0 when it is desired that the end product formed should contain the minimum amount of such impurities-and also' for the purpose of econ omy in the use of formaldehyde, to keep the proportion of the formaldehyde used in relation to the phenol at or below the ui-molecular pro ortion, to then determine the amount of res phenol in the solution after completion of the reaction, and to add a sufficient amount of hexa-methylene-tetro-unin or other body containing methylene-groups capable of reaction, to combine with e free eno V P As has been noted above, the product formed in water-solution, according to my present invention, differs from that contained in water-solution described in my other application Serial No. 780,453 referred to, in that it continues in water solution after the precipitation of the alkaline earth as described, by carbonic acid gas.

It further difi'ers chemically in that it eoncombined with carbonic acid.

As an example of a suitable .procedure in carrying out my present method, when it is desired to form a composition of thefirst application class mentioned above, that is, one which is not converted by heat into a non-plastic or infusible state, but which, upon being compressed in heated condition forms a compact, hard mass, the following may be cited: 3 to 27 parts of calcium oxid are hydrated to equal about 200 parts of milk of lime and mixed with 100 parts of phenol. From 60 to 75 parts of commercial 40 per cent. formaldehyde solution is then mixed with the phenol-lime solution which should be at a temperature notover 55 C. The reaction then proceeds at this temperature and is complete in from one-half hour to three hours. During the reaction, the tem perature rises and the containing vesel should be cooled to prevent the temperature from rising above 66 C. The product thus formed, which is still in water-solution, is then mixed with from 70 to 300 parts of filling material, which may be awood flour, asbestos fiber, cotton flocks, or any of the well known inert powdered fillers or mixtures of the same. After mixing, the moist mass is exposed to carbon-dioxid fintil the mass is neutralized, the completion of neutralization being determined by suitable indicative tests or it may be noted by observing the" completion of absorption of the gas by the maSS. The mass is then dried at a temperature of from 100 to 120 C. and may subsequently be molded in closed molds, or it may be compressed into slabs or other suitable forms previous to molding in open or flash molds by heat and pressure.

As an example of a composition of the second class described, namely one which is transformed by heat into' an infusible, insoluble state, the solution to be mixed with the filling materials may be the same as in the above example, with the addition of hexa methylene tetra amin, suflicient in amount to combine with the free phenol contained in the solution. Usually from 7 to 15 parts of the hexa-methylene-tetraamin will be required to be added to the solution after the completion of the reaction in the solution described in Example 1. I prefer, however, instead of adding such an amount of hexa-methylene-tetraamin, for the purpose described, to increase the amount, of formaldehyde in the initial reaction to an equi-molecular proportion, and subsequently to add an amount of hexamethylene-tetra-amin less than the amount given above in Example 2, the amount of heXa-methylene-tetra-amin to be added depending on the amount of free phenol contained in the product in solution, which amount will be less than that present in the composition of Example 1.

To make an enamel or lacquer, carbondioxid is passed through the solution after the initial reaction described above, until a neutral reaction is given by suitable indicators. The solution is then filtered from the precipitate of calcium carbonate and after ascertaining the amount of free phenol contained in the reaction product in solution, an amount of hexa-methylene-tetraamin suflicient to combine therewith is added. Strontium and barium oxids or hydroxids may be used in lace of the lime in proportions which are c emically equivalent to the proportions given above for the lime.

In the specification and claims the phrase substantlal amount of an alkaline earth metal oxid or the like is to be understood as meaning asufiicient amount to form a phenolate with the phenol when mixed therewith, or such an amount as will facilitate the reaction and form a water-soluble product in the reactions herein described. The alkali metal oxids or alkaline earth metal oxids referred to herein are also to be understood as including the corresponding hydroxids. Furthermore, under the name of phenol alcOhOls I mean to designate not only the first member of the series, oxy-benzyl-alcohol, but also the water-soluble homologues of the same or mixtures of these products as obtained by the above process by the treatment of commercial phenols or cresols. By the term formaldehyde I mean to include the polymers of formaldehyde and generally such substances as are equivalent thereto in the above described process. Likewise, when I refer to phenol in the claims, the

homologues or derivatives thereof equivalent to the same in this process are included. While, j as above stated, my present invention chiefly comprises a process in which a product comprising phenol-alcohols is formed in water-solution with the aid of a considerable amount of an alkaline earth metal oxid, and the latter neutralized and, precipitated as a water-insoluble, electrically-insulating salt, it. should be noted that as a sub-process my invention comprises broadly the neutralization and precipitation by a suitable mineral acid, by the method disclosed, and the removal, of the alkaline earth metal oxid used as condensing agent in any process for forming phenolic condensation products in which an alkaline earth metal oxid is used as a condensing agent and a product soluble in a suitable solvent may be formed. For example, a resinous partial condensation product may be formed of phenol and formaldehyde with the aid of an alkaline earth metal oxid, such as calcium hydrate, which product may be soluble in alcohol and other solvents, but not in water, and in which the condensing agent ma be present in a small proportion, if desired. The partial condensation product thus formed may be dissolved in a suitable solvent, such as alcohol, and the alkaline earth neutralized by a mineral acid, as described above. The acid, which may be carbonic or sulfuric, should be used in Lust the proportion to'exactly neutralize t e base, or 1n a little less proportion than s'uflicient to nontralize all ofthe base. An insoluble, insu-' lating, salt will thus be preci itated out, either the carbonate or the su fate of the alkaline earth metal used. The preferred method is to pass'carbonic acid gas throu h the solution, in the' same manner as escribed above in Exam le 1 of the process involving the water-solu le product. The salt thus precipitated which is, of course, insoluble in alcohol as well as in water, may be separated from the solution containing the condensation product, by filtration, when with the aid of a basic condensin agent andv the latter neutralized by a suitab e acid in a suitable solution, such as alcohol, to form an electrically-insulating compound. That a plication, however, claims specifically t e process in which the basic condensing agent used, which may be, for example, sodium hydrate or ammonia, is neutralized by a fatty acid, in which case there is no precipitation of the salt formed. Accordingly, in the present application will be claimed the process in which a mineral acid is used to precipitate out a salt of an alkaline earth metal,

used as a condensing agent, from asuitable solution, which is not limited to either water or alcohol, containing a henolic condensation product soluble therein. In the present appllcation also will be claimed the process in which a suitable mineral acid is used, s ecifically carbon dioxid, to neutralize an recipitate as an insulating salt the alka ine earth employed in any process for forming an alkaline water solution of a .phenolmethylene condensation product which may' be dissolved in water b the aid of the alkaline earth metal oxid; h' it will be noted, covers as to these features th the process described and prin'ci ally claimed herein, in which henol-alcoho are formed by reaction 0 phenol and formaldehyde with a lar proportion of basic condensing agent, an theprocess described and claimed my ap lication Serial No. 780,453 prevlously referred to, in which a phenolresin is ut in alkaline water-solution and neutralize with the resultant preci itation of both the resin and an insolublesa t of the basic agent. The latter application is however'limited in some of its specific claims to the use of an organic acid suchas rosin as the neutrahzingazgpn t, the oxid of an alkali metal such as um orfotassium being used as the condensing dissolving agent in this specific case. Having now described -my invention what I claim and desire to secure by Letters Patcut is as follows:

1. The process of forming a plastic substance which com rises mixing her phenol, formaldehy e, water and 'formed, with a suitable mineral acid to precipitate a non-water-soluble electrically insulatin salt, and drying the mass;

3. T e process of forming stance which comprises causing phenol and formaldeh dc to react in the resence of a substantia amount of an a line earth metal oxid and water to form a watersoluble product containing phenol alcohols, neutralizing the solution with a mineral acid which will form a water-insoluble insulating compound with the alkaline earth, and recipitate said compound out of the solution, and dr the mass.

4. T e process of forming a plastic sub-' stance wh1ch comprises causing. phenol and formaldehyde to react in the presence ofva substantial amount of calcium hydrate to form'a water-soluble product, neutralizing with carbonic acid and thereby preci i calcium carbonate from the solution an dryinlg the mass.

5. n a process of forming a plastic sub stance which comprises causing phenol and formaldehyde to react in the presence of a substantia amount of calcium hydrate to form a water-soluble product, the ste of neutralizing the said-hydrate with carhznic acid and thereby precipitating calcium carbonate from the solution and separating the solution from the calcium carbonate by fil tration.

6. The process of forming a plastic substance which consists in causing phenol and formaldehyde to react in the resence of.an alkaline earth and waterorm a watersoluble condensation roduct comprising phenol alcohols, neut ing the solution to process of forming a plastic suba plastic subprecipitate a non-water-soluble salt of the alkaline earth, drying the mass, and converting the same by heat treatment into a non-water-soluble body comprising a more highly condensed reaction product.

7. The process of forming a plastic substance which comprises mixing together a substantial proportion of an alkaline earth metal oxid, phenol, water and formaldehyde in a proportion not greater than equi-molecular in relation to the phenol, causing a reaction to form a water-soluble .condensation product in water and free phenol, neutralizing the solution with a suitable mineral' acid to precipitate a non-water-soluble salt of the alkaline earth metal, adding a methylene-containing substance, soluble in the solution, and drying the mass.

8. The process of forming a plastic substance which comprises mixing to ether phenol, formaldehyde, water and a su stantial proportion of an alkaline earth metal oxid, causing a reaction to form a watersoluble product comprising phenol-alcohols, in water and free phenol, neutralizing the solution with a mineral acid which will form a water-insoluble compound with the alkaline earth metal, and cause said compound to precipitate out of the solution, adding a methylene-containing substance, soluble in the solution, and drying the mass.

9. The process of forming a plastic substance which consists in the formation of a phenol-alcohol in waterand phenol-solution with the aid of a substantial amount of an alkaline earth metal oxid, treating the solution to precipitate out the alkaline earth metal as a water-insoluble salt, adding a methylene-containing substance suificient to combine with the free phenol on subsequent heat treatment, drying the mass, and con-' verting the same by heat treatment into a non-water-soluble body comprising agmore highly condensed reaction product.

10. In a process of :formin a plastic substance which comprises the ormation of a phenol-alcohol in waterand phenol-solution, the step which comprises adding to the solution a methylene-containing body suflicient to combine on subsequent heat treatment with the free phenol in the solution.

11. The process of forming a plastic substance which comprises causing phenol and formaldehyde to react in the presence of a substantial amount of calcium hydrate to form a water-soluble product, neutralizing with carbonic acid and thereby precipitating calcium carbonate from the solution, drying the mass, and converting the same by heat treatment into a non-water-soluble body comprising a more highly condensed reaction product.

12. In a process of forming a plastic substance which comprises causing phenol and formaldehyde to react in the presence of an alkaline earth metal oxid, to form a soluble product, the step of neutralizing a suitable solution of the same with a mineral acid which will precipitate out an insoluble, electrically-insulating salt of the alkaline earth metal, and separating the solution from the salt by filtration.

13. The process of forming a plastic substance which consists in forming an alkaline water solution of a phenol-methylene condensation product with the aid of an alkaline earth, exposing the same to carbondioxid gas until the mass is neutralized, and drying the mass.

14. The process of forming a plastic sub stance which consists in forming an alkaline water solution of a phenol-methylene condensation product with the aid of an alkaline earth, neutralizing the mass with a mineral acid, adapted to precipitate a waterinsoluble electrically-insulating salt, and in a proportion calculated to leave no excess of the acid after the neutralization, and drying the mass.

This specification signed and witnessed this 1st day of August, 1913.

JONAS W. AYLSWORTH.

Witnesses:

WILLIAM A. HARDY, FREDERICK BACHMANN. 

